The present invention relates generally to battery charging systems, and more particularly, to low cost battery charging systems for directly charging batteries of a spacecraft without the use of power conditioners.
Existing spacecraft developed by the assignee of the present invention use either of two battery charging systems that employ power converters to regulate and control battery charging current, or dedicated charge arrays in conjunction with switching relays to charge batteries directly. Tempo and FOS-II spacecraft are examples of the first system and the Intelsat VII spacecraft is an example of the second system.
In these conventional spacecraft, the use of power conditioners increases the mass and cost of the spacecraft, and also increases the thermal dissipation requirements of the spacecraft. In such conventional spacecraft, during periods of solar array shadowing, or at summer solstice when charging requirements are reduced and when charging requirements are minimal, additional solar array power is not used to power the payload, but instead is used to recharge the batteries. Furthermore, in conventional spacecraft, battery charger failures adversely affect the reliability of the spacecraft.
It would be desirable to have battery charging systems for use in a spacecraft that directly charges its batteries and which overcomes the limitations of conventional systems. Accordingly, it is an objective of the present invention to provide for low cost battery charging systems for directly charging batteries of a spacecraft without the use of power conditioners.